DESCRIPTION: This is an SBIR grant (Phase I) application to develop and test in vitro ribozymes targeted at the CCR5 co-receptor for M-tropic primary HIV-1 isolates. The applicants will test selected ribozymes initially in PM1 cells, later in primary T-cells and the progeny of stem cells, using various viral vectors and promoters. PROPOSED COMMERCIAL APPLICATION: Proposed commercial application not available.